Machine for digging soil

ABSTRACT

In a digging machine a rotor with spades is driven around a digging axis, said spades being tiltably mounted on said rotor. A guide member for guiding the tilting movement of said spades is improved so that the tilting of the spades is accelerated during an angular displacement of the rotor greater than 45*, resulting in an increase of the permissable rotational speed of the rotor and therefore in an increase of the capacity of the machine.

0 United States Patent 1151 3,705,629 Vissers 1 Dec. 12, 1972 [s41 MACHINE FOR DIGGING SOIL 3,352,366 11/1967 Vissers ..172/94 Inventor: Herbert vissers Nieuvbvennep, 3,331,448 7/1967 Vrssers ..172/94 Netherlands FOREIGN PATENTS 0R APPLICATIONS [73] Assignee: Landbouwerktuigen-en Machine- 717,798 9/1965 Canada ..172/94 fabriek H. Vissers N.V., Binnenweg, Rotterdam, Netherlands Primary Examiner--Robert E. Pulfrey Assistant Examiner-Stephen C. Pellegrino [22] 1970 Attorney-Amide, Smiley, Snyder and Butrum [21] Appl. No.: 9,686

[57] ABSTRACT [30] Foreign Application Priority Data In a diggingmachinea rotor with spades is driven around a dlggmg axis, said spades being tiltably Feb. 5, 1969 Netherlands ..69.02244 mounted on said rotor,

V A guide member for guiding the tilting movement of [52] US. Cl. ..l72/94, 172/95, 1177250151426, said Spades is improved so that the tilting of the Spades 51 I t Cl Rolb 33/00 is accelerated during an angular displacement of the I} rotor greater than 50 resulting in an increase f the [58] Field Of Search ..l72/94, 71, 112, 95, 546 permissable rotational speed of the rotor and there fore in an increase of the capacity of the machine. [56] References Cited 1 7 Claims, 9 Drawing Figures UNITED STATES PATENTS 3,012,616 12/1961 Horowitz ..172/94 111 25 TT 'T -1 l/p j E :IY 25 I i '18 T i l l9 1 i 1 21 i; I

20 1 ,5 i X i m I I I 27 I I I i 5 I'. I g4 28 PATENTEDBEB 12 1912 3. 705,629

SHEET 3 OF 3 INVENTOR Hzeam 7' 1/ 5 /95 PATENTEDBEC 12 1912 3. 705.629

sum a or a INVENTOR BY in M 4 WQ Q 7 4253/41 ATTORNEY MACHINE FOR DIGGING SOIL The invention relates to a machine for digging soil comprising a mobile frame, a driven rotor mounted for rotation in said frame around a digging axis, and at least one circular set of spades which are each mounted in the rotor to tilt around a tilting axis transverse to the digging axis and are each coupled to a guide member guided by a cam member so shaped that each of said spades tilts as it rises.

A machine of the kind specified is known. In the prior art machine the spade tilting is accelerated during a first angular displacement of the rotor of 45, while the deceleration of spade tilting takes place during the subsequent angular displacement of the rotor of 45. Due to the risk that when they lift clods from the soil they will displace subjacent soil, in the prior art machine the permissible rotational speed of the rotor and therefore the capacity of the machine are limited.

The invention improves the machine described hereinbefore by accelerating spade tilting during an angular displacement of the rotor greater than 45.

In the machine according to the invention the permissible rotational speed and therefore the capacity are higher than those of the prior art machine. The time available for the deceleration of spade tilting is less in the machine according to the invention than in the prior art machine, but this is no disadvantage to the tilting mechanism, since the mass to be decelerated is substantially smaller than the mass to be accelerated, because the tilting movement of the clod must be accelerated by the tilting mechanism, but not decelerated thereby. It is even advantageous to decelerate the tilting movement considerably, to enable the clods to be more readily released form the spades.

These and other features of the invention will be clearly gathered from the following description with reference to the drawings, wherein:

FIG. 1 is a plan view of a preferred embodiment of the machine according to the invention;

FIG. 2 is a side elevation of the machine shown in FIG. 1, showing only one circular set of spades;

FIG. 3 is a section, taken on the line III-III in FIG. 1;

FIG. 4 is a section, to an enlarged scale, taken on the line IV-IV in FIG. 1;

FIG. 5 is a section, taken on the line V-V in FIG. 4;

FIG. 6 shows the movement of the cam of a cam member in a prior art machine;

FIG. 7 shows the movement, corresponding to FIG. 6, in the machine illustrated in FIGS. 1-5;

FIG. 8 shows the movement, corresponding to FIG. 6, in a variant embodiment of the machine according to the invention, and

FIG. 9 shows the movement, corresponding to FIG. 6, in a second variant of the machine according to the invention.

The machine according to the invention comprises a frame 1 suspended by means of suspension rods3 from a tractor (not shown). The machine also has a driven tubular rotor 5 which is mounted for rotation in the frame 1 around a digging axis 4 and to which six circular sets 7 of three spades 6 each are attached. In the frame 1 a camshaft 8 stationary during operations is mounted to pivot around the digging axis 4. The camshaft 8 has a cam member 9 for each circular set 7.

Each spade 6 is mounted on the rotor 5, via a pin 10 bearing a pinion 12, to tilt around a tilting axis 11 transverse of the digging axis 4. The pinion 12 engages in a rack 13 mounted with provision for displacement axially of the digging axis 4 in the rotor 5. The rack 13 bears a guide member 14 which engages a groove 15 matching a cam 16 in the cam member 9.

The position of plane c of the camshaft 8 can be adjusted in relation to the vertical b through an angle a of, for instance, a maximum of 10 to -l0, by a disc 18 coupled to the camshaft 8 engaging an adjusting member 19 adjustably disposed on a rod 20 by means of a screw 21. The rod 20 can be displaced into the frame 1 against the force of a compression spring 22. Whenever, due to abnormal circumstances, the spades 6 exert too much torque on the camshaft 8, the camshaft 8 together with the disc 18 rotates against the action of the compression spring 22, so that the camshaft 8 co-rotates with the rotor 5.

The camshaft 8 is so arranged that spade tilting around the tilting axis 11 starts when the spade 6 passes the plane 0. The angular displacement of the rotor is offset from the plane 0 in FIG. 6-9, the spade tilting angle k 0.

Cam 17 (cf. FIG. 6) of the prior art machine is sinusoidal, while the spades tilt through an angle of 120.

In contrast, the cam 16 in the machine illustrated in FIG. 1-5, is not sinus-oidal, but as shown in FIG. 7. During an angular displacement cal of the rotor of spade tilting is very slightly accelerated, and during an angular displacement de of the rotor of 20 it is strongly decelerated. During angular displacement fg of the rotor, the spade 6 is tilted back into its starting position, in which it remains until the following tilting, again beginning at c. At the place e the spade tilting angle is 92 (instead of 120), and this proved to be adequate. In this way the required acceleration is further reduced during the angular displacement cd of the rotor.

Preferably the cam member has the cam 23 of FIG. 8, which is so shaped that during angular displacement st of the rotor of 15 the acceleration is small, for instance increases gradually, so that the force required for acceleration is still low at that period, where the force on the spade for loosening the clod from the ground is great. Cam 23 is so constructed that acceleration during angular displacement tu of the rotor is constant, the tilting movement is uniform during the angular displacement uv of the rotor, and the tilting is considerably decelerated during angular displacement vw of the rotor. During angular displacement xy of the rotor the spade tilts back again.

The preferred cam 24 (FIG. 9) differs from cam 23 by the feature that with the spade tilting concerning cam 24 is suddenly decelerated. To this end, cam 24 is completely straight over angular displacement nj of the rotor until the maximum tilting angle of 92 is reached, when the tilting suddenly terminates.

A machine having a cam like this can reach a speed of 53 rpm. and a digging speed (arrow 2) of 3 km per hour with a cam of this kind, a working depth of 30 cm and a rotor diameter of cm. The capacity of the machine according to the invention is substantially greater than that of the prior art machine.

The spades 6 mainly consist of a narrow spade blade 25, a bowed member 26 engaging said blade 25 outside the center thereof.

Each circular set 7 has a matching retaining member 27 so bent as to extend at the inner side of the passing spade blade 25. The arrangement of the retaining members 27 on carrier 28, the shape of the retaining members 27 and the shape of the spades 6 are such (cf. the drawings) that in each of their tilted positions, the spades 6 can pass the retaining members 27. If the spade tilting mechanism becomes accidentally locked, the camshaft 8 co-rotates with the rotor 5, and the spades 6 remain in any tilted position, the spades 6 do not knock against the retaining members 27. The latter can therefore be coupled to the frame 1 in a fixed position, without the interposition of springs or similar means yielding on overloading. The carrier 28 consists of a shaft which is pivotably mounted in the frame 1 and has an arm 29 which can be adjusted to various pivoted positions on the frame 1 by means of a screw 30. The pivoted positions are selected in dependence on the position of the camshaft 8 adjusted by means of adjusting member 19.

Disposed on the rear side of the machine is a soil guide 31 mainly consisting of a shaft 32 pivotably mounted in the frame 1, and a number, for instance two, of guide rods 38 for each circular set 7. The shaft 32 can be adjusted to various positions on the frame 1 by means of an attached arm 34 and a screw 35. The adjusted position is so chosen that the soil guide 31 guides the dug-up clods hurled backwards by the spades 6 in their flight to the place for which they are intended.

What I claim is:

1. In a soil digging machine of the type including a mobile frame, a driven rotor mounted on said frame for rotation about a digging axis, a circumferentially spaced set of spades carried by said rotor for rotation therewith, each spade including a bowed member having a blade fixed to one end thereof, means mounting the opposite end of each bowed member on said rotor for rotation therewith and for oscillation about a tilting axis transverse to said digging axis, and cam means acting between said frame and each bowed member for sequentially controlling each associated to move about its tilting axis, as soon as such blade is substantially beneath said rotor, from a normal position in which a corresponding bowed member is disposed in a plane substantially perpendicular to said digging axis to a fully tilted position attained when such blade is substantially behind said rotor so that movement of each blade from normal to fully tilted positions is restricted to approximately 90 rotation of said rotor, and then back to said normal position during each revolution of said rotor, the improvement wherein:

each cam means includes ramp means for accelerating its associated blade from its normal position during an angular displacement of said rotor which is substantially greater than 45 and for thereafter decelerating such blade to said fully tilted position during an angular rotation of said rotor which is substantially less than 45 whereby although the deceleration is of much greater magnitude than the acceleration, the acceleration is distributed over a relatively large angular displacement of the rotor to permit high rotational speed of said rotor. 2. In a soil digging machine as defined in claim 1 wherein said said ramp means includes a portion for efectin co stant velocit tiltin of i as ociated s ade in a period between said acce eration and said deceleration.

3. In a soil digging machine as defined in claim 2 wherein each said cam means includes a cam and follower means connecting said cam to an associated spade for oscillating such spade through anangle of about 92.

4. In a soil digging machine as defined in claim 1 wherein each said cam means includes a cam and follower means connecting said cam to an associated spade for oscillating such spade through an angle of about 92.

5. In a soil digging machine as defined in claim 1 wherein the angular displacement of said rotor during which each of said spade accelerations occur is in the order of 6. In a soil digging machine as defined in claim 5 wherein the angular displacement of said rotor during which each of said decelerations occur is in the order of about 12 or less.

7. In a soil digging machine as defined in claim 1 wherein the angular displacement of said rotor during which each of said decelerations occur is in the order of about 12 or less.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,705,629 Dated. Dec. 12,1972

Inventm-(S) Herbert Vissers It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Under "Poreign Application Priority Data" Feb. 5, 1969 should read Feb. 13, 1969 Signed and sealed this 27th day of March 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents ORM PC3-1050 (1069) USCOMM-DC 60376-P69 V US GOVERNMENT PRINTING OFFICE I969 0-366-334 

1. In a soil digging machine of the type including a mobile frame, a driven rotor mounted on said frame for rotation about a digging axis, a circumferentially spaced set of spades carried by said rotor for rotation therewith, each spade including a bowed member having a blade fixed to one end thereof, means mounting the opposite end of each bowed member on said rotor for rotation therewith and for oscillation about a tilting axis transverse to said digging axis, and cam means acting between said frame and each bowed member for sequentially controlling each associated to move about its tilting axis, as soon as such blade is substantially beneath said rotor, from a normal position in which a corresponding bowed member is disposed in a plane substantially perpendicular to said digging axis to a fully tilted position attained when such blade is substantially behind said rotor so that movement of each blade from normal to fully tilted positions is restricted to approximately 90* rotation of said rotor, and then back to said normal position during each revolution of said rotor, the improvement wherein: each cam means includes ramp means for accelerating its associated blade from its normal position during an angular displacement of said rotor which is substantially greater than 45* and for thereafter decelerating such blade to said fully tilted position during an angular rotation of said rotor which is substantially less than 45* whereby although the deceleration is of much greater magnitude than the acceleration, the acceleration is distributed over a relatively large angular displacement of the rotor to permit high rotational speed of said rotor.
 2. In a soil digging machine as defined in claim 1 wherein said said ramp means includes a portion for effecting constant velocity tilting of its associated spade in a period between said acceleration and said deceleration.
 3. In a soil digging machine as defined in claim 2 wherein each said cam means includes a cam and follower means connecting said cam to an associated spade for oscillating such spade through an angle of about 92*.
 4. In a soil digging machine as defined in claim 1 wherein each said cam means includes a cam and follower means connecting said cam to an associated spade for oscillating such spade through an angle of about 92* .
 5. In a soil digging machine as defined in claim 1 wherein the angular Displacement of said rotor during which each of said spade accelerations occur is in the order of 70*.
 6. In a soil digging machine as defined in claim 5 wherein the angular displacement of said rotor during which each of said decelerations occur is in the order of about 12* or less.
 7. In a soil digging machine as defined in claim 1 wherein the angular displacement of said rotor during which each of said decelerations occur is in the order of about 12* or less. 